1. Field of the Invention
The present invention is directed to a printing character matrix and a process of forming the matrix.
2. Prior Art
Character matrices, which are now presently used in photo-type setting devices, have been made in various forms. One of these forms consists of using a support which comprises a glass disk or a disk of transparent material, which is covered with a layer of photographic emulsion. The various signs, symbols or characters are formed in the emulsion layer on the disk by a photographic process. The disk may include several rows of characters, signs or symbols arranged concentrically with one another.
Another form of character matrix utilizes a cylinder, which has appropriate apertures. A character support, such as a bit of photographic film, is fitted in front of each of the apertures in the cylinder wall. These film bits are fitted mechanically either by gluing them in each of the apertures or by holding them magnetically in the apertures of the cylinder wall.
Another possibility of a character matrix consists of a frame composed of a plurality of segments, such as four segments. Photographic film bits, which carry the various characters are glued on each of these segments, which are usually made of light metal.
Character matrices such as the above described type have special advantages in their use. However, in the case where the user chooses a matrix having the shape of a cylinder or drum, they will always encounter trouble both with the fastening and interchangeability of the various fonts making up the matrix. Since the fastening of the fonts requires particular care, these forms of matrices are expensive to make and produce. Moreover, the various fonts are provided in most cases with metal parts carried over the photographic film, which fact produces major registry problems.